Solution of cellulose esters



Patented Got. 4, 1 927.

UNITED; STATES PATENT 'F11 ;E

Josnrn o. nnvrnson, or rrrrsntmon, PENNSYLVANIA, assrenon 'ro cannrnn ms QARBON' CHEMICALS OQBIBORATION, A CORPORATION OF NEW YORK.

SOLUTION or cELLuLo'sn ns'rnns.

No Drawing.

The invention relates to solutions of cellulose esters, such as are employed, for example, as lacquers 'formetal; and 1ts ob ect is to provide improved compositions of this class. 5 Many solvents for cellulose, esters, such as the nitrate and acetate esters, are known. Butyl and amyl acetates are often used; and

' 'acetylenetetrachlorid, ethylene chlorhydrin,

and diacetone alcohol HB Z O (C Q)Z) I -may also be mentioned. There are many others.

As compared w1th known solutions of cellulose esters, solutions containing the monoor dialkyl ethers of ethylene glycol exhibit certain advantageous qualities. The ethers may be use'd with-or without other solvents or diluents to form a vehicle for the cellulose ester, since they are compatible with known solutions of cellulose esters, improve or at least do not injure the filmdeposited, and are solvents for many gums and resins which are commonly employed in lacquers.

Among the compounds of this class there may be mentioned the following; I

Boiling olnt 7 Compound. v C

Monomethyl ether 125 Dimethyl ether 83 Monoethyl ether 135 Diethyl ether 124 Monopropyl ether 150 Diprop lether 160 Monoa'l yl ether 159 Diisobutyl 'ether l a l a 181 Amyl and butyl acetates have strong dis-- agreeable odors whereas certain of the ethers of the class mentioned, particular? the monoethyl ether, are practically o orless.

The ethers contain no acid radical and 'do' not hydrolyze, and they possess other advantageou characteristics. 1

The alkyl ethers of ethylene glycol dis- I solve cellulose nitrate readily, and some of them can'be combined with other substances to produce remarkable solvents for cellulose .acetate. Thus a mixture of equal parts of monoethyl ether and ethylene dichlorid will dissolve suflicient cellulose acetate. to make a lacquer in three or four; minutes, giving a clear, non-viscous solutlon in that t me,

Application filed June 13; 1924. Serial No. 7 1 9,891,

whereas with some solvents now. employed aperiod of as much as eight or ten hours, with rolllng or kneading of the components, is necessary'to attain the same result, In connection with the foregoing it is of interest to note that neither the monoethyl ether or ethylene dichlorid alone a solvent for cellulose acetate. 7 v

.' An excellent lacquer maybe made from a solution 'of cellulose acetate in a mixture of the-monoethylether and ethylene dichlorid by-add ng to t he solution a small quantity of a lllgll-bOlllllg solvent for the cellulose acetate, such as gl ycol monoor diacetate, acetylene tetrachlorid, diacetone alcohol, or the like. This highboiling addition assists Y in the production of a transparent adherent film on drying a coat of the lacquer, and as l ttle as'1%' or 2% of the high-boiling additlon may be effective for this purpose, Solvents and diluents other than those mentioned may also be incorporated in the solution. Compositions according to my invention. may be free from. li uids other than the ethylene glycol ethers, ut'it usually will be preferable to employ an auxiliary solvent or diluent for reasons of economy or to modify the properties of the solution. Useful solutions may be made as follows: Three weights "of nitro-cellulose is dissolved in 40 weights 2. A compos1tionof matter comprising a solution of cellulose acetate containing a substantial proportion of an alkyl ether of ethy leneglycol. Y I v v 3. A composition of matter comprising a solution of a cellulose ester containing asubstantial proportion of ethylether.

4. A composition of matter comprising a solutionof cellulose acetate containing a ethylene glycolmono v substantial proportion of ethylene glycol monoethyl ether.

chlorid.

6. A composition'ofimatter comprising a solution of cellulose acetate containing ethylene dichlorid, ethylene glycol monoethyl ether, and a solvent forcellulose acetate having a higher boiling point than said ether. Intestimony whereof, I afllx my signa- 'ture.

JOSEPH G. DAVIDSON. 

